PLASMA ATRIAL-NATRIURETIC-PEPTIDE IS ELEVATED IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

Study objectives. To determine if plasma levels of atrial natriuretic peptide are elevated in patients with hypertrophic cardiomyopathy and to determine the relationship of atrial natriuretic peptide to symptom s and echocardiographic indices of left ventricular structure and dias tolic function in these patients. Design. A prospective study in which atrial natriuretic peptide was measured in peripheral venous plasma i n 14 patients (age 44 +/- 14 years) with hypertrophic cardiomyopathy a nd 17 healthy controls. Echocardiography was performed in all cases an d 30 controls to examine indices of left heart structure and function. All patients underwent clinical evaluation. Results. The concentratio n of atrial natriuretic peptide was significantly higher in patients w ith hypertrophic cardiomyopathy than controls, (17.86 +/- 8.72 vs. 6.2 2 +/- 3.26 pmol/l, P = 0.0001). Diastolic dysfunction was observed in 11 of 14 patients with hypertrophic cardiomyopathy. No correlation was demonstrated between atrial natriuretic peptide levels and the degree of diastolic dysfunction, septal or free wall thickness, left atrial size, degree of mitral regurgitation or New York Heart Association fun ctional class. Conclusions. Plasma levels of atrial natriuretic peptid e are elevated in patients with hypertrophic cardiomyopathy but do not correlate with symptoms or echocardiographically-derived indices of l eft ventricular structure or diastolic function.